ENDOCRINE PANCREAS Anatomy Location Pancreatic Islets of Langerhans
- Slides: 18
ENDOCRINE PANCREAS
Anatomy • Location • Pancreatic Islets (of Langerhans) – – Alpha cells Beta cells Delta cells F-cells
Hormones
Insulin • Chemistry – Protein/Peptide • 51 amino acids • 2 -chains – & – 2 disulfide bridges – Proinsulin • 86 amino acid protein • C peptide • Peptidases
Insulin Action
Insulin Receptor • • • Kinase Autophosphorylation Phosphorylation of proteins Translocation of GLUT-4 Down-regulation
Glucose Transporter Proteins • • • GLUT-1 GLUT-2 GLUT-3 GLUT-4: INSULIN REGULATED GLUT-5
Basic effect of Insulin • Promotes uptake of glucose from the blood • Promotes storage of energyproducing nutrients
Effect of Insulin on the Liver • Stimulates glycogenesis • Stimulates protein synthesis • Increased production of triglycerides, cholesterol, and VLDL • Inhibits glycogenolysis • Inhibits ketogenesis • Inhibits gluconeogenesis
Effect of Insulin on Skeletal Muscle • Promotes protein synthesis • Stimulates glycogen synthesis
Effect of Insulin on Fat Cells • Promotes triglyceride storage
Insulin Regulation • Factors that stimulate insulin secretion – High serum glucose – High serum amino acids – Enteric hormones • Factors that inhibit insulin secretion – Glucagon – Somatostatin – -adrenergic stimulation
Insulin Control SERUM AMINO ACIDS SERUM GLUCOSE GUT HORMONES GLUCAGON SOMATOSTATIN -CELL PANCREATIC ISLET INSULIN -ADRENERGIC SERUM GLUCOSE UPTAKE LIVER & MUSCLE
Glucagon • Chemistry – 29 amino acid peptide – Proglucagon • Action – Antagonizes the action of insulin – Acts primarily on the liver – Stimulates glycogenolysis – Stimulates gluconeogenesis – Stimulates ketogenesis
Glucagon Regulation SOMATOSTATIN BLOOD SUGAR SYMPATHETIC INNERVATION PARASYMPATHETIC INNERVATION G-I HORMONES CORTISOL PANCREAS -CELL GLUCAGON GLUCOSE LIVER & MUSCLE
Somatostatin • Chemistry – 14 amino acid peptide – Prosomatostatin – G-protein linked receptor – Produced and secreted by many tissues • Action – Paracrine Factor – Inhibits insulin & glucagon secretion • Regulation
Pancreatic Peptide • Chemistry – 36 amino acid peptide • Action – unknown • Regulation – Serum levels increase after a meal, but do not increase after glucose infusion – Vagotomy abolishes response to meal
Glucose Homeostasis GLYCOGENOLYSIS GLUCONEOGENESIS LIVER & MUSCLE GLUCAGON ISLET -CELLS HYPERGLYCEMIC HORMONES MEALS SERUM GLUCOSE NORMAL SERUM GLUCOSE 80 -120 mg/dl ISLET -CELLS INSULIN LIVER & MUSCLE SERUM GLUCOSE UPTAKE METABOLIC DEMANDS
- Islets of langerhans location in pancreas
- Pancreas location
- Baylor
- Lamina propria of tongue
- Endocrine anatomy
- Disacharides
- Small intestine extends from
- Anatomy of the pancreas
- Galbader
- Anatomy and physiology of pancreas
- Gastric gland
- Pancreas anatomy histology
- Langerhans adacıkları
- Pankreas stent
- Celulas de langerhans
- Kenadie jourdin bromley
- Isole di langerhans
- Spijsverteringshormonen
- Frederick grant bantingfor sale